Directions:for the 3500 and 3800 to start up a new or dormant toilet, mix 2 Tbs with 5 gallons of water and pour over the stools. Thereafter add 1 Tbs per week per dog. For model numbers 2000 and 3000 to start up a new or dormant unit, fill the unit with water and mix in 2 Tbs of digester powder. Thereafter add 1 Tbs per week. For the old 900 Doggie Dooley follow the directions for the 3500 Doggie Dooley Toilet. For best results with all units, mix the digester powder with water before pouring into the unit.